Blender + Pyside or PyQt4
Official blender distributions include the standard python library with a few modules disabled (such as tkinter and test). I'm quite sure that numpy is the only third party module to be included.

Blender uses it's own GUI widget library and provides a python api for us to add custom interface layouts. While you can ask the developers to add other modules, you shouldn't expect other third party modules to be added to the standard install.

You do have several options -


Add third party modules to your installation of blender. You can find several questions like this one that expand on this option.
Remove the included python so that blender uses the system installed python. You can also build your own version that is configured to not include it's own python version. This gives blender access to the same python modules you have access to in your python scripts.
Run blender in background mode to perform tasks that you have scripted.
Build blender as a python module. If you are using scripts to automate tasks you could use blender without a GUI and control it from your app.